Magnetoresistive effect element, magnetic memory element magnetic memory device and manufacturing methods thereof

ABSTRACT

In a magnetoresistive effect element using a ferromagnetic tunnel junction having a tunnel barrier layer sandwiched between at least a pair of ferromagnetic layers, a magnetization free layer comprising one of the ferromagnetic layers is composed of a single layer of a material having an amorphous or microcrystal structure or a material layer the main portion of which has an amorphous or microcrystal structure. The magnetoresistive effect element can produce excellent magnetic-resistance characteristics, and a magnetic memory element and a magnetic memory device using the magnetoresistive effect element as a memory element thereof can improve both of write and read characteristics at the same time.

BACKGROUND OF THE INVENTION

The present invention relates to a magnetoresistive effect element, amagnetic memory element, a magnetic memory device and manufacturingmethods thereof, and particularly to a magnetoresistive effect elementhaving stable magnetic characteristics, a magnetic memory elementoperable as a magnetic nonvolatile memory element, a magnetic memorydevice composed of the magnetic memory element and manufacturing methodsthereof.

As information communication devices, in particular, personal smalldevices such as personal digital assistants are making great spread,elements such as memories and logics comprising informationcommunication device are requested to have higher performance such ashigher integration degree, higher operation speed and lower powerconsumption. In particular, technologies for making nonvolatile memoriesbecome higher in density and larger in storage capacity areprogressively increasing their importance as technologies for replacinghard disk and optical disc that cannot be essentially miniaturizedbecause they have movable portions.

As nonvolatile memories, there may be enumerated flash memories usingsemiconductors and FRAM (Ferro electric Random Access Memory) usingferroelectric material and the like.

However, the flash memory encounters with a drawback that its writespeed is as slow as the microsecond order.

On the other hand, it is pointed out that the FRAM has a problem inwhich it cannot be rewritten so many times.

A magnetic memory device called an MRAM (Magnetic Random Access Memory),(e.g. see “Wang et al., IEEE Trans. Magn. 33 (1977), 4498), receives aremarkable attention as a nonvolatile memory which can overcome thesedrawbacks.

Since this MRAM is simple in structure, it can easily be integrated at ahigher integration degree. Moreover, since it is able to memorizeinformation based upon the rotation of magnetic moment, it can berewritten so many times. It is also expected that the access time ofthis magnetic random access memory will be very high, and it was alreadyconfirmed that it can be operated at the access time of nanosecondorder.

A magnetoresistive effect element for use with this MRAM, in particular,a tunnel magnetoresistive (Tunnel Magnetoresistance) element isfundamentally composed of a lamination layer structure of aferromagnetic tunnel junction of ferromagnetic layer/tunnel barrierlayer/ferromagnetic layer.

This element generates magnetoresistive effect in response to a relativeangle between the magnetizations of the two magnetic layers when anexternal magnetic field is applied to the ferromagnetic layers under thecondition in which a constant current is flowing through theferromagnetic layers. To be concrete, when the magnetization directionsof the two magnetic layers are anti-parallel to each other, a resistancevalue is maximized. When they are parallel to each other, a resistancevalue is minimized. Function of memory element can be demonstrated bycreating the anti-parallel state and the parallel state with applicationof the external magnetic field when the magnetization direction of oneferromagnetic layer is inverted.

This resistance changing ratio is expressed by the following equation(1) where P₁, P₂ represent spin polarizabilities of the respectivemagnetic layers.2P₁P₂/(1−P₁P₂)  (1)The resistance changing ratio increases as the respective spinpolarizabilities increase. With respect to a relationship betweenmaterials for use with ferromagnetic layers and this resistance changingratio, ferromagnetic chemical elements of Fe group such as Fe, Co, Niand alloys of three kinds thereof have already been reported so far.

With respect to writing of information in the MRAM, in order to storeinformation in the selected memory element of the magnetic memoryelement, this magnetic random access memory is composed of a pluralityof bit write lines, a plurality of word lines intersecting these bitwrite lines and TMR elements provided at crossing points between thesebit write lines and word write lines as magnetic memory elements. Then,when information is written only in the element located at the selectedcrossing point of these bit write line and word write line by utilizingan asteroid characteristic (see Japanese laid-open patent applicationNo. 10-116490, for example).

The bit write line and the word write line used in that case are made ofconductive thin films such as Cu and Al which are generally used bysemiconductor devices. In this case, when information is written in amagnetic memory element of which the inverted magnetic field forgenerating the above-mentioned inversion of the magnetization is 40[Oe], for example, by the bit write line and the word write line, thebit write line and the word write line being 0.35 μm in width, a currentof approximately 10 mA was required. In this case, assuming that thethickness of the write line be the same as the line width, then acurrent density required at that time becomes 8.0×10⁻⁶ A/cm². There isthen a risk that breaking of wire will be caused by electromigration.

Accordingly, from a standpoint of the occurrence of electromigration andfurther in view of a problem of heat generated by the recording currentand from a standpoint of decreasing a power consumption, this recordingcurrent has to be decreased.

As a means for decreasing the recording current, there is enumerated amethod of decreasing an inverted magnetic field of a TMR element, i.e.,coercive force.

The coercive force of this TMR element is determined based upon thesize, shape of the element, the film arrangement and the selection ofthe materials. However, although it is desired that the size of theelement should be miniaturized for the purpose of increasing a recordingdensity of the MRAM, for example, the coercive force of the elementtends to increase due to the miniaturization of the element. Therefore,the decrease of the coercive force should be attained from the materialstandpoint.

If the magnetic characteristic of the magnetic memory element isdispersed at every element and the magnetic characteristic is dispersedwhen the same element is used repeatedly, the selective writing usingthe asteroid characteristic becomes difficult.

Therefore, the magnetic memory element is requested to have a magneticcharacteristic by which an ideal asteroid curve can be drawn. In orderto draw the ideal asteroid curve, an R—H (resistance-magnetic field)curve obtained when TMR is measured should not have noises such as aBarkhausen noise, a rectangle property of a waveform should beexcellent, the magnetization state should be stable and the dispersionof the coercive force Hc should be small.

Information may be read out from the magnetic memory element as follows.When magnetic moments of one ferromagnetic layer and the otherferromagnetic layer across the tunnel barrier layer are anti-parallel toeach other and a resistance value is high, this state is referred to asa “1”, for example. Conversely, when the respective magnetic moments areparallel to each other and a resistance value is low, this state isreferred to as a “0”. Then, information is read out from the magneticmemory element based upon a difference current obtained at a constantbias voltage or a difference voltage obtained at a constant bias currentin these “1” and “0” states.

Accordingly, when resistance dispersions between the elements areidentical to each other, a higher TMR ratio (R_(max)−R_(min)) R_(min)where a resistance value R_(min) represents the low resistance state anda resistance value R_(max) represents the high resistance state) isadvantageous and hence a magnetic memory device that can operate at ahigh speed, having a high integration degree and having a low error ratecan be realized.

A magnetic memory element having a fundamental structure offerromagnetic layer/tunnel barrier layer/ferromagnetic layer has a biasvoltage dependence of TMR ratio., and it is known that the TMR ratiodecreases as the bias voltage increases.

When information is read out from the element based upon the differencecurrent or the difference voltage, it is known that the TMR ratio takesthe maximum value of the read signal at a voltage (Vh) which decreasesby half depending upon the bias voltage dependence. Accordingly, asmaller bias voltage dependence is effective for decreasing read errorin the MRAM.

Therefore, the TMR element for use with the MRAM should satisfy theabove-mentioned write characteristic requirements and theabove-mentioned read characteristic requirements at the same time.

However, when the magnetization free layer is generally made of amagnetic material composed of only ferromagnetic transition metalchemical elements of Co, Fe, Ni, if the alloy compositions by which thespin polarizabilities shown by P₁ and P₂ in the aforementioned equation(1) are increased are selected, then the coercive force Hc tends toincrease.

For example, when the magnetization free layer is made of Co₇₅Fe₂₅(atomic %) alloy and the like, although a TMR ratio having large spinpolarizabilities and which is greater than 40% can be maintained, it isunavoidable that the coercive force also increases. But instead, whenthe magnetization free layer is made of an Ni₈₀Fe₂₀ (atomic %) alloywhich is referred to as a “permalloy” and the like, although the spinpolarizabilities are small as compared with the case in which themagnetization free layer is made of the Co₇₅Fe₂₅ (atomic %) alloy sothat the TMR ratio is lowered up to about 33%.

Further, when the magnetization free layer is made of a Co₉₀ Fe₁₀(atomic %) alloy, although a TMR ratio of about 37% can be obtained andits coercive force can become an intermediate value between theabove-mentioned Co₇₅Fe₂₅ (atomic %) alloy and Ni₈₉Fe₂₀ (atomic %) alloy,this magnetization free layer is inferior in rectangle property of anR—H loop and an asteroid characteristic by which information can bewritten in the element cannot be obtained.

SUMMARY OF THE INVENTION

The present invention is to provide a magnetoresistive effect elementhaving excellent rectangle property, improved noise and stable magneticcharacteristic, a magnetic memory element having these characteristics,improved characteristic dispersion and excellent asteroidcharacteristics, a magnetic memory device whose write characteristicsand read characteristics are improved by this magnetic memory elementand methods of manufacturing the magnetoresistive effect element, themagnetic memory element and the magnetic memory device.

A magnetoresistive effect element according to the present invention isa magnetoresistive effect element using a ferromagnetic tunnel junctionhaving a tunnel barrier layer sandwiched between at least a pair offerromagnetic layers.

A magnetization free layer composed of one of the ferromagnetic layersis comprised of a single layer of a material having an amorphous ormicrocrystal structure or a material layer the main portion of which hasan amorphous or microcrystal structure.

This magnetization free layer contains at least one kind or more thantwo kinds of metalloid chemical element and metallic chemical elementwhich are 3B-group chemical element, 4B-group chemical element, 5B-groupchemical element relative to at least one kind or more than two kinds ofcomponents of ferromagnetic chemical elements of Fe, Co, Ni.

As the metalloid chemical element and the metallic chemical element,there can be used any one kind or more than two kinds of B, C, Al, Si,P, Ga, Ge, As, In, Sn, Sb, Tl, Pb, Bi.

More preferably, any one kind or more than two kinds of B, Al, Si, Geshould be used as the metalloid chemical element and the metallicchemical element.

The metalloid chemical element content and the metallic chemical elementcontent of this magnetization free layer are selected within a range offrom 5 to 35 atomic %.

Alternatively, the magnetization free layer may contain at least onekind or more than two kinds of 4A-group chemical element, 5A-groupchemical element on a periodic table relative to at least one kind ormore than two kinds of ferromagnetic chemical elements of Fe, Co, Ni.

In this case, as the 4A-group chemical element and the 5A-group chemicalelement of the magnetization free layer, there can be used at least onekind or more than two kinds of Ti, Zr, Nb, Hf, Ta.

The 4A-group chemical element content and the 5A-group chemical elementcontent of this magnetization free layer are selected in a range of from5 to 25 atomic %.

Moreover, the magnetization free layer may contain at least one kind ormore than two kinds of metalloid chemical element and metallic chemicalelement which are 3B-group chemical element, 4B-group chemical element,5B-group chemical element on a periodic table relative to at least onekind or more than two kinds of components of ferromagnetic chemicalelements of Fe, Co, Ni.

Moreover, in this magnetization free layer, i.e., the magnetization freelayer that contains at least one kind or more than two kinds ofmetalloid chemical element and metallic chemical element which are3B-group chemical element, 4B-group chemical element, 5B-group chemicalelement on a periodic table and at least one kind or more than two kindsof 4A-group chemical element, 5A-group chemical element on a periodictable relative to at least one kind or more than two kinds offerromagnetic chemical elements of Fe, Co, Ni, this magnetization freelayer contains added chemical elements of Cu, N, O, S, the contents ofwhich are selected to be less than 2 atomic %.

Further, in the magnetoresistive effect element according to the presentinvention, the above-mentioned main portion of the magnetization freelayer is located on the side of the tunnel barrier layer.

Then, the magnetic memory element according to the present invention isa magnetic memory element based upon a magnetoresistive effect elementusing a ferromagnetic tunnel junction having a tunnel barrier layersandwiched between at least a pair of ferromagnetic layers. Aninformation storage layer based upon a magnetization free layer composedof one of the ferromagnetic layers is comprised of a single layer of amaterial having an amorphous or microcrystal structure or a materiallayer the main portion of which has an amorphous or microcrystalstructure.

The information storage layer in this magnetic memory element hasarrangements similar to those of the magnetization free layer in theabove-mentioned magnetoresistive effect element.

Moreover, a magnetic memory device according to the present inventionincludes a word line and a bit line crossing each other in athree-dimensional fashion and a magnetic memory element composed of amagnetoresistive effect element having the above-mentioned respectivearrangements of the present invention located at the portions in whichthese word lines and bit lines cross each other.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A and 1B are respectively cross-sectional views of an example ofa magnetoresistive effect element or a magnetic memory element accordingto the present invention;

FIG. 2 is a perspective view of a main portion of an example of amagnetic memory device according to the present invention;

FIG. 3 is a schematic cross-sectional view showing an example of amagnetic memory element according to the present invention;

FIG. 4A is a schematic plan view of a test element sample of a magneticmemory element;

FIG. 4B is a cross-sectional view taken along the line A-A in FIG. 4A;

FIG. 5A is a diagram of characteristic curves showing a relationshipamong kinds, added amounts and coercive forces of 3B-group addedchemical element to 5B-group added chemical element in the compositionof (Co₉₀Fe₁₀)_(100-x)M_(x) (M represents B, Si, Al, Ge, Mg, Zn) andshows measured results of 2A-group Mg and 2B-group Zn as comparativeexamples;

FIG. 5B is a diagram of characteristic curves showing a relationshipamong kinds, added amounts and TMR ratios of 3B-group added chemicalelement to 5B-group added chemical element in the composition of(Co₉₀Fe₁₀)_(100-x)M_(x) (M represents B, Si, Al, Ge, Mg, Zn) and showsmeasured results of 2A-group Mg and 2B-group Zn as comparative examples;

FIG. 6A is a diagram showing a relationship between a composition of amaterial of a magnetization free layer and a coercive force measuredwhen Si and two kinds of B, C, Al, P were added at the same time as thecompositions of (Co₉₀Fe₁₀)₇₅Si₁₅M₁₀ (M represents B, C, Al, P)

FIG. 6B is a diagram showing a relationship between a composition of amaterial of a magnetization free layer and a TMR ratio measured when Siand two kinds of B, C, Al, P were added at the same time as thecompositions of (Co₉₀Fe₁₀)₇₅Si₁₅M₁₀ (M represents B, C, Al, P);

FIG. 7A is a diagram showing a relationship between a compositiondependence (B is added with a constant added amount of 20 atomic %) of aferromagnetic transition metal of a magnetization free layer and acoercive force in the composition of (Co_(x)Fe_(y)Ni_(z))₈₀B₂₀ and showsmeasured results obtained when B is not added to the composition as acomparative example;

FIG. 7B is a diagram showing a relationship between a compositiondependence (B is added with a constant added amount of 20 atomic %) of aferromagnetic transition metal of a magnetization free layer and a TMRratio in the composition of (Co_(x)Fe_(y)Ni_(z))₈₀B₂₀ and shows measuredresults obtained when B is not added to the composition as a comparativeexample;

FIG. 8A is a diagram showing a relationship among added chemicalelements added amounts and coercive forces of a magnetization free layermaterial with 4A-group chemical element and 5A-group chemical elementadded in the composition of (Co₉₀Fe₁₀)_(100-x)M_(x) (M represents Ti,Zr, Nb, Ta of 4A-group chemical element and 5A-group chemical element)

FIG. 8B is a diagram showing a relationship among added chemicalelements, added amounts and TMR ratios of a magnetization free layermaterial with 4A-group chemical element and 5A-group chemical elementadded in the composition of (Co₉₀Fe₁₀)_(100-x)M_(x) (M represents Ti,Zr, Nb, Ta of 4A-group chemical element and 5A-group chemical element)

FIG. 9A is a diagram showing a relationship among added chemicalelements, added amounts and coercive forces of a magnetization freelayer material into which 10 atomic % of B, 4A-group chemical elementand 5A-group chemical element were added at the same time as in thecomposition of (Co₉₀Fe₁₀)_(90-x)M_(x)B₁₀ (M represents Ti, Zr, Nb, Ta of4A-group chemical element and 5A-group chemical element);

FIG. 9B is a diagram showing a relationship among added chemicalelements, added amounts and TMR ratios of a magnetization free layermaterial into which 10 atomic % of B, 4A-group chemical element and5A-group chemical element were added at the same time as in thecomposition of (Co₉₀Fe₁₀)_(90-x)M_(x)B₁₀ (M represents Ti, Zr, Nb, Ta of4A-group chemical element and 5A-group chemical element);

FIG. 10A is a diagram showing measured results of a coercive force of amagnetization free layer in which Cu, Nb, Si, B are added to CoFe at thesame time;

FIG. 10B is a diagram showing measured results of a TMR ratio of amagnetization free layer in which Cu, Nb, Si, B are added to CoFe at thesame time;

FIG. 11A is a diagram showing a relationship between a substratetemperature required when a magnetization free layer is deposited and aTMR ratio;

FIG. 11B is a diagram showing a relationship between a substratetemperature required when a magnetization free layer is deposited and aTMR ratio;

FIG. 12A is a diagram showing measured coercive forces obtained when amagnetization free layer has a lamination layer structure composed of acrystal material and an amorphous material;

FIG. 12B is a diagram showing measured TMR ratios obtained when amagnetization free layer has a lamination layer structure composed of acrystal material and an amorphous material;

FIG. 13A is a diagram showing measured values of bias voltagedependences with respect to TMR ratios in the magnetization free layeraccording to the present invention;

FIG. 13B is a diagram showing characteristic curves obtained when biasvoltage dependences with respect to TMR ratios in the magnetization freelayer according to the present invention were plotted;

FIG. 14 is a diagram showing resistance versus external magnetic fieldcurves obtained when a magnetization free layer is composed of(Co₉₀Fe₁₀)₈₀B₂₀ and Co₉₀Fe₁₀;

FIG. 15A is a diagram showing asteroid characteristic curves obtainedwhen a magnetization free layer is composed of (Co₉₀Fe₁₀)₈₀B₂₀;

FIG. 15B is a diagram showing asteroid characteristic curves obtainedwhen a magnetization free layer is composed of Co₉₀Fe₁₀; and

FIG. 16 is a block diagram showing a magnetic memory device.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

A magnetoresistive effect element according to an embodiment of thepresent invention is a magnetoresistive effect element suitable for useas a magnetic sensor, for example.

Moreover, a magnetic memory element according to the present inventionis a memory element that can be applied to each memory element of amagnetic memory device.

Further, a magnetic memory device according to the present invention hasan arrangement in which a plurality of bit write lines (hereinafterreferred to as “bit lines” or “BL”) and word write lines (hereinafterreferred to as “word lines” or “WL” or “WWL”) are crossing each other ina three-dimensional fashion, magnetic memory elements according to thepresent invention being located at crossing points where the bit linesand the word lines are crossing each other in a three-dimensionalfashion.

First, the fundamental arrangements of the magnetoresistive effectelement and the magnetic memory element according to the presentinvention are equal to each other, and therefore these magnetoresistiveeffect element and magnetic memory element will be described.

[Magnetoresistive Effect Element and Magnetic Memory Element]

A magnetoresistive effect element and a magnetic memory elementaccording to the present invention have a ferromagnetic tunnel junctionstructure having a tunnel barrier layer sandwiched between at least apair of ferromagnetic layers.

FIG. 1A is a schematic cross-sectional view of an example of amagnetoresistive effect element or a magnetic memory element 1 basedupon a TMR element having this ferromagnetic tunnel junction structure.In this embodiment, an underlayer 3 is formed on a substrate, e.g. Sisubstrate, and an antiferromagnetic layer 4 is formed on the substratethrough this underlayer 3. A ferromagnetic tunnel junction portion 8 onwhich a ferromagnetic layer 5 (hereinafter referred to as a “firstferromagnetic layer”), a tunnel barrier layer 6 and a ferromagneticlayer 7 (hereinafter referred to as a “second ferromagnetic layer”) arelaminated in that order is formed on the antiferromagnetic layer.

Then, a protective layer 9 which might be called a top-coat layer isformed on this ferromagnetic tunnel junction portion 8.

The first ferromagnetic layer 5 is a magnetization fixed layer of whichthe magnetization direction is fixed, and the second ferromagnetic layer7 is a magnetization free layer of which the magnetization direction isinverted, which is an information storage layer in the magnetic memoryelement.

This magnetization free layer or the second ferromagnetic layer 7comprising the information storage layer has an amorphous ormicrocrystal structure in which the following alloy chemical elementswere added to transition metals (hereinafter referred to as an “FMTM”)of at least one kind or more than two kinds of Fe, Ni, Co.

Since the magnetization free layer and the information storage layerbased upon the ferromagnetic layer 7 has the amorphous or microcrystalstructure as described above, it can decrease a coercive force while aspin polarizability of the FMTM is being maintained, it can obtain asoft magnetic characteristic to improve a Barkhausen noise in an R—Hcurve and a rectangle property, it can serve as the information storagelayer to decrease dispersions in writing information when the magneticfield is inverted repeatedly and therefore can obtain satisfactory writecharacteristics. At the same time, it can realize a high TMR ratio andcan obtain excellent read characteristics in which a bias dependencecharacteristic has been improved.

As chemical elements added to the FMTM that can achieve theabove-mentioned effects, i.e., objects, chemical elements are roughlyclassified into the following classes 1 to 3.

Class 1. Addition of metalloid chemical elements and metallic chemicalelements of 3B-group chemical elements to 5B-group chemical elements ona periodic table.

Class 2. Addition of 4A-group chemical elements and 5A-group chemicalelements on a periodic table.

Class 3. Addition of either of or both of the chemical elements on theclasses 1 and 2 and addition of very small amounts of chemical elementsof Cu, O, N, etc.

In the magnetoresistive effect element and the magnetic memory elementaccording to the present invention, the second ferromagnetic layer 7contains the FMTM that may contain the alloy added components shown inthe above-described classes 1 and 2 for the purpose of decreasing thecoercive force while maintaining the spin polarizability. Insofar as theabove-mentioned objects are achieved, the second ferromagnetic layer maycontain the FMTM and other components than the added components shown onthe above-described classes 1 and 2.

The above-described class 1 intends to make the magnetization free layerbecome amorphous. As examples of alloy-based components for making themagnetization free layer become amorphous in which one kind of metalloidis added to the FMTM, there may be listed alloy-based components inwhich 3B-group chemical elements to 5B-group chemical elements are addedto the FMTM on a periodic table, such as FMTM-SI alloy, FMTM-B alloy,FMTM-P alloy and FMTM-C alloy. However, the FMTM-Si alloy and the FMTM-Balloy should preferably be used as the above-mentioned alloy-basedcomponent.

Insofar as the above-mentioned objects can be attained, the alloy-basedcomponent may contain more than two kinds of 3B-group and 4B-groupmetalloids on the periodic table. As alloy-based components that can belisted in this case, there may be enumerated a large number ofcombinations such as FMTM-B—C alloy, FMTM-B—P alloy, FMTM-B—Ge alloy,FMTM-Si—B alloy, FMTM-Si—P alloy, FMTM-Si—C alloy, FMTM-Si—Al alloy . .. . Of these alloy-based components, FMTM-B alloy, FMTM-Si—B alloy andFMTM-Si—Al alloy should preferably be used as the above-mentionedalloy-based component.

The above-described class 2 also intends to achieve effects forimproving ability for making the magnetization free layer becomeamorphous or improving fine structure of crystal grains, 4A-groupchemical elements and 5A-group chemical elements (preferably Ti, Zr, Hf,Nb, Ta) are added to the above-mentioned alloy-based component. Asalloy-based components, there may be listed combinations such as FMTM-Tialloy, FMTM-Zr alloy, FMTM-Hf alloy, FMTM-Nb alloy, FMTM-Ta alloy,FMTM-Zr—Nb alloy, FMTM-Ta—Nb alloy, FMTM-Ti—Zr alloy., FMTM-Zr—Ta alloy,FMTM-Zr—Nb—Ta alloy, FMTM-Zr—Nb alloy . . . . However, of thesealloy-based components, there should preferably be listed FMTM-Zr—Nballoy, FMTM-Zr—Ta alloy, FMTM-Ta—Nb alloy and the like.

The above-described class 3 intends to improve ability for making themagnetization free layer become amorphous or improving fine structure ofcrystal grains rather than effects achieved by the metalloids on theclasses 1 and 2 and in which the metalloid chemical elements, themetallic elements and other chemical elements are added to alloy-basedcomponents. As the alloy-based components in this example, there may belisted innumerable combinations such as ternary alloys such as FMTM-B—Nballoy, FMTM-B—Zr alloy, FMTM-Si—Al alloy, FMTM-Si—Nb alloy, FMTM-Si—Zralloy, quaternary alloys such as FMTM-Si—B—Al alloy, FMTM-Si—B—Nb alloy. . . . Moreover, main components of chemical elements added to the FMTMmay belong to the above-described classes 1 and 2 and theabove-mentioned alloy-based component may contain other classes such asCu, O, N. Of these alloy-based components, there should preferably belisted FMTM-Si—Al alloy, FMTM-Zr—B alloy, FMTM-Si—Cu alloy, FMTM-Nb—SiBalloy, FMTM-Si—B—Cu alloy, FMTM-Si—B—Zr—Cu alloy, FMTM-Si—B—Nb—Cu alloyand the like.

As described above, when the alloy elements are added to themagnetization free layer to thereby decrease a coercive force while aspin polarizability for obtaining a large resistance changing ratio ofthe information storage layer is being maintained, if the added chemicalelements such as 3B-group metalloids to 5B-group metalloids and 4A-groupchemical elements and 5A-group chemical elements relative to the FMTMare increased too much, then the amount of the ferromagnetic transitionmetal chemical element FMTM decreases excessively so that the filmcharacteristic lost its ferromagnetism unavoidably. If a resistancevalue of a target increases too much, then when this magnetic layer isdeposited by a suitable method such as a DC magnetron sputtering method,it becomes difficult to deposit the magnetic layer, and hence a troublearises, in which a film of high quality cannot be deposited.

In that case, although the cause is not yet clear, troubles arise, inwhich a magnetic resistance changing ratio decreases. Therefore, it isto be desired that the added amounts of metalloid chemical elements andmetallic chemical elements (preferably B, Si, Al, Ge) which are 3B-groupchemical elements to 5B-group chemical elements on the periodic table inthe case of the class 1 should be less than 50% although theabove-mentioned added amounts may change depending on the composition ofTM.

If the amount of added chemical elements is too large, then it isfrequently observed that the film characteristic no longer demonstratesits ferromagnetism. Accordingly, in order to obtain the amorphous ormicrocrystal system structure, if one kind or more than two kinds ofelements are in use, then it is to be desired that the total amount ofadded chemical amounts should fall within a range of from 5 to 35 atomic%.

Even when the magnetic layer is given the microcrystal structure, if thechemical element B is added to the magnetization free layer, then solong as ferromagnetic deposits such as FeB, Fe₂B, Fe₃B, Co₂B and Co₃Bcan be obtained, it is to be desired that the added amount of thischemical element should fall within a range of from 5 to 35 atomic %.

When 4A-group chemical element and 5A-group chemical element(preferably, Ti, Zr, Hf, Nb, Ta) on the above-described class 2 areadded to the magnetization free layer, if the added amount of thesechemical elements is too large, then when the magnetization free layercannot have the amorphous structure and loses its ferromagnetism so thata magnetic characteristic is degraded, thereby lowering a TMR ratio. Forthese reasons, it is desirable that the added amount should be about 20atomic % at most and that it should be less than the foregoing numericalvalue.

When chemical elements on both of the above-described classes 1 and 2are added to the magnetization free layer, if the added amount is toolarge, then the magnetization free layer loses its ferromagnetism and itbecomes difficult to obtain a desired amorphous structure or a desiredmicrocrystal system as well. Therefore, it is to be desired that theamounts of these chemical elements added to the FMTM should be less thanapproximately 35 atomic % similarly to the case of the 3B-group chemicalelements to the 5B-group chemical elements on the class 1.

So long as the chemical elements on the classes 1 and 2 are both addedto the FMTM and these chemical elements are main components of the addedchemical elements, the magnetization free layer may contain a very smallamount of chemical elements such as Cu, O, S. This will apply for otherchemical elements added as well.

Well-known amorphous and microcrystal soft magnetic materials that areappearing in the page 298 of “HANDBOOK OF MAGNETIC ENGINEERING writtenby Kenji Kawanishi, Soshin Chikazumi, Yoshifumi Sakurai” can be used solong as they meet with the requirements that have been enumerated sofar.

When the second ferromagnetic layer, i.e., the magnetization free layeror the information storage layer is comprised of the magnetic materiallayers having these amorphous and microcrystal structures, in order toachieve effects for reducing a coercive force, i.e., inverted magneticfield and effects for maintaining a TMR ratio by the amorphous ormicrocrystal structure, it is to be desired that this magnetization freelayer or the information storage layer should have a single-layerstructure made of this magnetic material or that most of the mainportion of the magnetization free layer or the information storage layershould be comprised of this magnetic material layer.

On the other hand, as shown in FIG. 1A, for example, since themagnetization fixed layer includes the antiferromagnetic material layer4 which is coupled to the first ferromagnetic layer 5 in anantiferromagnetic fashion, even when a current magnetic field forrecording information on a magnetic memory, for example, is applied tothe magnetoresistive effect element or the magnetic memory element, themagnetization direction of the magnetization fixed layer can beprevented from being inverted.

A ferromagnetic material comprising the first ferromagnetic layer 5 ofthis magnetization fixed layer is not limited to some specificferromagnetic material but an alloy material composed of one kind ormore than two kinds of Fe, Ni, Co can be used as the above ferromagneticmaterial.

Moreover, a material comprising the antiferromagnetic layer 4 may becomprised of Mn alloy such as Fe, Ni, Pt, Ir, Rh, Co and Ni oxide, etc.

FIG. 1B shows a schematic cross-sectional view of an example of themagnetoresistive effect element or the magnetic memory element. Asillustrated, the first ferromagnetic layer 5, i.e., the magnetizationfixed layer can be formed so as to have a lamination layer ferristructure composed of a first ferromagnetic material layer 51, anon-magnetic conductive layer 52 and a second ferromagnetic materiallayer 53.

Also in this case, the first ferromagnetic material layer 51 is incontact with the antiferromagnetic layer 4, and hence the magnetizationfixed layer 5 is given a strong magnetic anisotropy of one direction byexchange interaction acting on these two layers.

The conductive layer 52 in that case can be made of a suitable materialsuch as Ru, Cu, Cr, Au and As.

In FIG. 1B, elements and parts identical to those of FIG. 1A are denotedby identical reference numerals and therefore need not be described.

A tunnel barrier layer 6 is interposed between the first and secondferromagnetic layers 5 and 7 shown in FIGS. 1A and 1B as describedabove. This tunnel barrier layer lying between the two ferromagneticlayers plays a role not only to break a magnetic coupling between thefirst ferromagnetic layer 5, i.e., the magnetization fixed layer and themagnetization free layer or the information storage layer of the secondferromagnetic layer 7 but also to cause a tunnel current to flow.

This tunnel barrier layer 6 can be made of an insulating thin film layerof thin films of oxide such as Al, Mg, Si, Ca, nitride, halogenide andthe like.

[Manufacturing Methods of Magnetoresistive Effect Element and MemoryElement]

Respective layers, i.e., respective magnetic layers and conductive layercomprising these magnetoresistive effect element and magnetic memoryelement can be formed by a vapor deposition method, sputtering, i.e.,sputtering vapor deposition method.

Then, the tunnel barrier layer 6 can be formed by oxidizing or nitridinga metal film thus formed by sputtering, for example. Alternatively, thetunnel barrier layer can be formed by a chemical vapor deposition (CVD)method using organic metals, oxygen, ozone, nitrogen or halogen andhalogenated gas.

The magnetization free layer, e.g. the second ferromagnetic layer 7comprising the information recording layer can be manufactured by avapor-phase growth method such as a vacuum deposition method, asputtering vapor deposition method and a CVD (Chemical Vapor Deposition)method or other suitable method such as electrolytic plating andnonelectrolytic plating.

However, when a TMR film has a thickness ranging from several nanometersto several 10s of nanometers as in the case of comprising an MRAM, ingeneral, it is to be desired that the magnetization free layer or thesecond ferromagnetic layer should be formed by a vapor-phase growthmethod such as sputtering.

When the magnetization free layer or the second ferromagnetic layer isdeposited by the above-mentioned vapor-phase growth method, for example,if it is deposited under the condition in which the substrate 2 is notheated, then an amorphous film can be deposited based upon compositionsof materials for depositing the film and deposition conditions.

Specifically, when the magnetization free layer based on the secondferromagnetic layer 7, e.g. information storage layer is formed so as tohave an amorphous film arrangement, since grain boundary does not existany longer, homogeneity within this ferromagnetic layer can be improved.Thus, even when the composition ratios of the FMTM components are equal,the magnetization free layer is formed as the amorphous magnetizationfree layer by addition of amorphous chemical elements, thereby making itpossible to decrease a coercive force.

In that case, in order to deposit the amorphous film, it is to bedesired that a substrate temperature required when the amorphous film isdeposited should be kept under 100° C. by a suitable method such ascooling.

Moreover, there can be used a method for generating finer crystalsystems by changing the film in the form of amorphous state to crystalstate. In this case, in order to demonstrate desired magneticcharacteristics, the crystal system should preferably be made finer andmore uniform, and it is desirable that a particle size should be madeunder at least 2 nm.

It is to be desired that a temperature in the heat treatment in thatcase should be a temperature higher than approximately a temperature atwhich the material may be crystallized and that this temperature shouldbe made lower than a temperature at which a particle size of depositedmicrocrystal may be increased by recrystallization.

A magnetic memory device according to an embodiment of the presentinvention will be described next.

[Magnetic Memory Device]

In a magnetic memory device according to the present invention, amagnetic memory element comprising a memory cell is comprised of theabove-mentioned magnetic memory element 1 according to the presentinvention.

This magnetic memory device can be formed so as to have a cross-pointtype MRAM array structure as FIG. 2 shows a perspective view of aschematic arrangement of a main portion of an example of this magneticmemory device and FIG. 3 shows a schematic cross-sectional view of onememory cell.

Specifically, this MRAM includes a plurality of word lines WL arrayed inparallel to each other and a plurality of bit lines BL arrayed inparallel to each other such that these bit lines may cross these wordlines in a three-dimensional fashion. The magnetic memory elements 1according to the present invention are located at portions in whichthese word lines WL and these bit lines BL cross each other in athree-dimensional fashion, memory cells 11 being constructed at theseintersecting portions.

FIG. 2 shows the magnetic memory device at its portion in which 3×3memory cells are disposed in a matrix fashion.

FIG. 3 shows a schematic cross-sectional view of this memory cell. Inthis case, a switching transistor 13 is formed on a semiconductorsubstrate 2 composed of a silicon substrate, i.e., semiconductor wafer,for example.

This transistor is comprised of an insulating gate field-effect typetransistor, e.g., MOS transistor. In this case, on the semiconductorsubstrate 2, there is formed a gate insulating layer 14 on which aninsulating gate portion with a gate electrode 15 deposited thereon isconstructed.

The semiconductor substrate 2 has a source region 16 and a drain region17 formed across the insulating gate portion. In this arrangement, thegate electrode 15 constructs a read word line RWL.

The semiconductor substrate 2 with this transistor 13 formed thereon hasa first interlayer insulator 31 formed thereon over the gate electrode15. Contact holes 18 are bored on the respective source region 16 anddrain region 17 of the first interlayer insulator 31 through theinterlayer insulator 31, and conductive plugs 19 are filled into therespective contact holes 18.

Then, an interconnection layer 20 for the source region 16 is depositedon the first interlayer insulator 31 over the conductive plug 19 that isbrought in contact with the source region 16.

Further, a second interlayer insulator 32 is formed on the firstinterlayer insulator 31 so as to cover the interconnection layer 20.

The contact hole 18 is bored on the second interlayer insulator 32 overthe conductive plug 19 in contact with the drain region 17, and theconductive plug 19 is filled into the contact hole.

A write word line WWL corresponding to the word line WL in FIG. 2 isformed on the second interlayer insulator 32 along the direction inwhich the read word line RWL, for example, extends.

A third interlayer insulator 33 made of silicon oxide, for example isformed on the second interlayer insulator 32 so as to cover the writeword line WWL. Also in the third interlayer insulator 33, the contacthole 18 is bored through the conductive plug 19 that is brought incontact with the drain region 17, and the conductive plug 19 is filledinto the contact hole.

Then, the underlayer 3 made of a conductive material, e.g., Ta is formedon the third interlayer insulator 33 in contact with the conductive plug19 that extends through this third interlayer insulator 33 as shown inFIGS. 1 to 3, for example, and the magnetic memory element 1 is formedon this underlayer 3.

Further, a fourth interlayer insulator 34 is formed on the underlayer 3so as to cover the magnetic memory element 1, and the bit line BL isformed on this underlayer insulator across the write word line WL.

A surface insulating layer is formed on the bit line BL according to theneed although not shown.

The above-mentioned first to fourth interlayer insulators, the surfaceinsulating layer and the like can be formed with application of plasmaCVD, for example.

These memory cells 11 are arrayed on the common semiconductor substrate2, i.e., semiconductor wafer in a matrix fashion as shown in FIG. 2.

Next, the antiferromagnetic layer 4 is regulated in magnetizationdirection, i.e., the antiferromagnetic layer 4 is magnetized in thepredetermined direction by a field anneal treatment, whereby themagnetization of the magnetization fixed layer 5 composed of aferromagnetic layer in contact with this antiferromagnetic layer 4 andwhich is coupled to this antiferromagnetic layer in an antiferromagneticfashion can be fixed to one direction.

In the magnetic memory device having this arrangement, when apredetermined current flows to the bit line BL and the write word lineWL (WWL), the magnetization direction of the magnetization free layer isinverted to record information by applying a predetermined writemagnetic field of a synthesized magnetic field of magnetic fields fromthe two bit line BL and write word line WL to the magnetoresistiveeffect element of the memory cell 11 at the selected intersection point,e.g., the magnetization free layer of the TMR element 1.

When information is read out from the magnetic memory device, thetransistor 13 is turned ON by applying a predetermined ON voltage to thegate electrode 15 of the transistor 13 relating to the selected memorycell from which information is read out, i.e., the read word line RWL tocause a read current to flow through the bit line BL and theinterconnection layer 20 of the source region 16 of the transistor 13,thereby resulting in information being read out from the memory cell.

When the magnetic memory device according to the present invention ismanufactured, the aforementioned manufacturing method can be applied tothe magnetic memory element.

Next, inventive examples will be described. While magnetic memoryelements in these inventive examples are suitable for use with thememory element of the aforementioned MRAM shown in FIGS. 2 and 3, it isneedless to say that they can be applied to magnetic memory elements inother semiconductor integrated circuits, electronic circuits and thelike.

INVENTIVE EXAMPLE 1

A magnetic memory element according to this inventive example was formedas a TMR element including a ferromagnetic tunnel junction portionhaving a fundamental structure based upon a lamination layer of theaforementioned ferromagnetic material layer 5/tunnel barrier layer6/ferromagnetic material layer 7, i.e., MTJ (Magnetic Tunnel. Junction).

In this case, the first ferromagnetic layer 5 is formed so as to have alamination layer ferri structure.

Moreover, in this case, as in the spin-valve type memory, theferromagnetic layer 5 is formed as the magnetization fixed layer, ofwhich the magnetization direction is fixed by the antiferromagneticlayer 4 so that the direction of the magnetization is constantly set tobe constant. The other ferromagnetic layer 7 is formed as themagnetization free layer, i.e., the information storage layers so thatthe direction of the magnetization is inverted with application ofexternal magnetic fields.

In this inventive example, as FIG. 4A shows a plan view of a mainportion of the magnetic memory element and as FIG. 4B shows across-sectional view taken along the line A-A′ in FIG. 4A, the switchingtransistor shown in FIG. 3 and the like were removed from this magneticmemory element in order to examine magnetoresistive characteristics ofthe element.

In this inventive example, first, we have prepared a. 0.525 mm-thick Sisemiconductor substrate 2 on which there has been formed a 300 nm-thickinsulating layer 12 composed of a heat oxide film.

A metal film comprising word lines was formed on the whole surface ofthis semiconductor substrate 2, and a word line WL that extends in onedirection was formed by pattern-etching according to photolithography.

At that time, in the etched portion other than the portion in which theword line WL is formed, the oxide film of the semiconductor substrate 2,i.e., the insulating film 12 was etched up to the depth of 5 nm.

The magnetic memory element (TMR element) 1 was formed on this word lineWL. This TMR element 1 had a lamination layer structure comprised ofunderlayer 3/antiferromagnetic layer 4/ferromagnetic material layer 51of first ferromagnetic layer/conductive layer 52, second ferromagneticmaterial layer 53/tunnel barrier layer 6/second ferromagnetic layer7/protective layer 8, in that order, from below. The arrangement of eachlayer has a lamination layer structure comprising Ta (3 nm)/PtMn (30nm)/Co₉₀Fe₁₀ (2 nm)/Ru (0.8)/Co₉₀Fe₁₀ (2 nm)/oxide film of Al (1nm)/(Co₉₀Fe₁₀)_(100-x)Ml_(x)/Ta (5 nm). (In the written form expressingthis lamination layer state, a suffix of each chemical elementrepresents an atomic % and a numerical value within each parenthesis andwhich is indicated at the unit of nm represents a film thickness of eachlayer. This will apply for the following descriptions as well) The TMRfilm 1 is composed of a part of this lamination layer film. To this end,a mask layer (not shown) was formed on the lamination layer film at itsportion in which the TMR element 1 is formed by a photoresist layer, andthe pattern of the TMR element 1 with elliptical flat surface was etchedby dry etching using photolithography.

The pattern of the TMR element 1 in that case had an elliptical shapewith a minor axis of 0.8 g m and a major axis of 1.6 μm.

Of this film arrangement, other portions than the tunnel barrier layerof the Al oxide were deposited by a DC magnetron sputtering method. Thetunnel barrier layer of the Al oxide was formed as follows. First, ametal Al film having a thickness of 1 nm was deposited by a DCsputtering system, and the tunnel barrier layer was formed byplasma-oxidizing a metal Al film with an oxygen:argon flow rate of 1:1at chamber gas pressure of 0.1 mTorr by an ICP (Inductive CoupledPlasma: inductive coupled plasma). The oxidation time may changedepending upon an ICP output and was selected to be 30 seconds in thisinventive example.

Thereafter, the test sample was annealed within a field anneal furnacewith application of an electric field of 10 [kOe] at 270° C. for 4hours, and the magnetization of the first ferromagnetic layer 5 wasfixed to one direction by effecting PtMn regulation heat treatment onthe antiferromagnetic layer 4.

In this inventive example, the composition of CoFe other than the secondferromagnetic layer 7 comprising the magnetization free layer(information storage layer) was selected to be Co₉₀Fe₁₀ (atomic %).Then, the composition of the second ferromagnetic layer 7 was selectedto be (Co₉₀Fe₁₀)_(100-x)Ml_(x), and in order to contrast the result ofthis inventive example with a result of Co₉₀Fe₁₀ alloy of a comparativeexample 1 which will be described later on, a ratio of ferromagnetictransition metal chemical elements of Co and Fe was fixed to Co₉₀: Fe₁₀and the amount of Ml (B, Si, Al, Ge) was changed from one atomic % to 40atomic %.

In the TMR element 1 formed on the above-mentioned substrate 2, as shownin FIG. 4B, an Al₂O₃ insulating layer 30 is treated by sputtering, anopening is formed through the TMR element 1 by etching usingphotolithography and a bit line BL extending in one direction crossingthe extending direction of the word line WL is formed over theinsulating layer 30 through this opening by deposition of a metal filmand pattern etching using photolithography.

Terminal pads 23 and 24 for use in measuring characteristics are formedon each of both ends of the respective word line WL and bit line BL atthe same time the word line and the bit line are formed.

INVENTIVE EXAMPLE 2

In the film arrangement of the TMR element 1, except that thecomposition of the second ferromagnetic layer 7, i.e., the magnetizationfree layer (information storage layer) was selected to be(Co₉₀Fe₁₀)₇₅Si₁₅Ml₁₀ and that Ml was selected to be B, C, P, Al, thisinventive example had a similar arrangement to that of the inventiveexample 1.

INVENTIVE EXAMPLE 3

In the film arrangement of the TMR element 1, except that thecomposition of the second ferromagnetic layer 7, i.e., the magnetizationfree layer (information storage layer) was selected to be(Co₉₀Fe₁₀)₈₀B₂₀, (Co₇₅Fe₂₅)₈₀B₂₀, (Co₅₀Fe₅₀)₈₀B₂₀, (Ni₈₀Fe₂₀)₈₀B₂₀, thisinventive example had a similar arrangement to that of the inventiveexample 1.

INVENTIVE EXAMPLE 4

In the film arrangement of the TMR element 1, except that thecomposition of the second ferromagnetic layer 7, i.e., the magnetizationfree layer (information storage layer) was selected to be(Co₉₀Fe₁₀)_(100-x)M2_(x), M2 was selected to be Ti, Zr, Nb, Ta and thatthe composition ratio was changed from 0 to 40 atomic %, this inventiveexample had a similar arrangement to that of the inventive example 1.

INVENTIVE EXAMPLE 5

In the film arrangement of the TMR element 1, except that thecomposition of the second ferromagnetic layer 7, i.e., the magnetizationfree layer (information storage layer) was selected to be(Co₉₀Fe₁₀)_(90-x)B₁₀M2_(x), M2 was selected to be Ti, Zr, Nb, Ta andthat the composition ratio was changed from 0 to 20 atomic %, thisinventive example had a similar arrangement to that of the inventiveexample 1.

INVENTIVE EXAMPLE 6

In the film arrangement of the TMR element 1, except that thecomposition of the second ferromagnetic layer 7, i.e., the magnetizationfree layer (information storage layer) was selected to be(Co₉₀Fe₁₀)_(73.5)Cu₁Nb₃Si_(13.5)B₉ and(Co₉₀Fe₁₀)_(73.5)Cu₁Nb₃Si_(16.5)B₆, this inventive example had a similararrangement to that of the inventive example 1.

INVENTIVE EXAMPLE 7

In this inventive example, the following two samples (1), (2) weremanufactured. In the film arrangement of the TMR element 1, the sample 1had the composition of the second ferromagnetic layer 7, i.e., themagnetization free layer (information storage layer) selected as

Substrate/Ta (3 nm)/PtMn (30 nm)/Co₉₀Fe₁₀ (2 nm)/Ru (0.8 nm)/Co₉₀Fe₁₀ (2nm)/oxide film of Al (1 nm) (Co₉₀Fe₁₀)₈₀B₂₀ (2 nm)/ Co₉₀Fe₁₀ (1 nm)/Ta(5 nm)

The sample 2 had the above-mentioned composition selected asSubstrate/Ta (3 nm)/PtMn (30 nm)/Co₉₀Fe₁₀ (2 nm)/Ru (0.8 nm)/Co₉₀Fe₁₀ (2nm)/oxide film of Al (1 nm) (Co₉₀Fe₁₀)₈₀B₂₀ (1 nm)/Co₉₀Fe₁₀ (1 nm)(Co₉₀Fe₁₀)₈₀B₂₀ (1 nm)/Ta (5 nm)

Except that the second ferromagnetic layer 7 has the above-mentionedarrangement, any of these samples (1) and (2) has a similar arrangementto that of the inventive example 1.

COMPARATIVE EXAMPLE 1

In the film arrangement of the TMR element 1, except that thecomposition of the second ferromagnetic layer 7, i.e., the magnetizationfree layer (information storage layer) was selected to be Co₉₀Fe₁₀,Co₇₅Fe₂₅, Co₅₀Fe₅₀, Ni₈₀Fe₂₀, this comparative example had a similararrangement to that of the inventive example 1.

COMPARATIVE EXAMPLE 2

In the film arrangement of the TMR element 1, the composition of thesecond ferromagnetic layer 7, i.e., the magnetization free layer(information storage layer) was selected to be

Substrate/Ta (3 nm)/PtMn (30 nm)/Co₉₀Fe₁₀ (2 nm)/Ru (0.8 nm)/Co₉₀Fe₁₀ (2nm)/oxide film of Al (1 nm)/(Co₉₀Fe₁₀)_(100-x)M3_(x) (3 nm)/Ta (5 nm)

In this film arrangement, the CoFe composition under the tunnel barrierlayer other than the magnetization free layer was selected to beCo₉₀Fe₁₀ (atomic %). With respect to the (Co₉₀Fe₁₀)_(100-x)M3_(x), inorder to contrast its result with the Co₉₀Fe₁₀ alloy of the comparativeexample 1, a ratio between the ferromagnetic transition metal chemicalelements of Co and Fe was fixed to Co₉₀Fe₁₀ (atomic %), the amount of M3(Mg, Zn) was changed from 1 atomic % to 40 atomic %.

COMPARATIVE EXAMPLE 3

In the film arrangement, the composition of the second ferromagneticlayer 7, i.e., magnetization free layer (information storage layer) wasselected to be Substrate/Ta (3 nm)/PtMn (30 nm)/Co₉₀Fe₁₀ (2 nm)/Ru (0.8nm)/Co₉₀Fe₁₀ (2 nm)/oxide film of Al (1 nm)/(Co₉₀Fe₁₀)_(90-x)B₁₀M3_(x)(3 nm)/Ta (5 nm)

In this film arrangement, the CoFe composition under the tunnel barrierlayer other than the magnetization free layer was selected to beCo₉₀Fe₁₀ (atomic %). This comparative example has a similar arrangementto that of the inventive example 1 except that with respect to the(Co₉₀Fe₁₀)_(90-x)B₁₀M3_(x), in order to contrast its result with theresult of the Co₉₀Fe₁₀ alloy of the comparative example 1, the ratiobetween the ferromagnetic transition metal chemical elements was fixedto Co: Fe=90:10 (atomic %) and the amount of the M3 (Mg, Zn) was changedfrom 1 atomic % to 40 atomic %.

COMPARATIVE EXAMPLE 4

In the film arrangement of the TMR element 1, this comparative examplehas a similar arrangement to that of the inventive example 1 except thata magnetization free layer is composed of a film having a composition of(Co₉₀Fe₁₀)₉₅B₅ and that a substrate temperature required when themagnetization free layer is deposited was selected in a range of from50° C. to 200° C.

COMPARATIVE EXAMPLE 5

In the film arrangement of the TMR element 1, this comparative examplehas a similar arrangement to that of the inventive example except thatthe second ferromagnetic layer 7 has a lamination layer structure suchas Substrate/Ta (3 nm)/PtMn (30 nm)/Co₉₀Fe₁₀(2 nm)/Ru (0.8 nm)/Co₉₀Fe₁₀(2 nm)/oxide film of Al (1 nm)/Co₉₀Fe₁₀ (2 nm) (Co₉₀Fe₁₀)₈₀B₂₀ (1 nm)/Ta(5 nm)

Characteristics of the above-mentioned inventive examples andcomparative examples were evaluated. When the magnetic memory element ofthe present invention is used as a memory element of a magnetic memorydevice, its magnetization free layer is inverted in magnetization as theinformation storage layer with application of a current magnetic field.In this characteristic evaluation, in order to evaluate thecharacteristics of the magnetic memory, the magnetization free layer wasinverted in magnetization with application of an external magnetic fieldand thereby characteristics were evaluated.

The TMR element 1 that is used to evaluate magnetic characteristics andTMR ratios was an ellipse-shaped element having a minor axis of 0.8 μmand a major axis of 1.6 μm.

A magnetic field for inverting the magnetization of the informationrecording layer is applied to the information storage layer in parallelto the easy axis of the magnetization. An intensity of the magneticfield for this measurement was selected to be 500 [Oe] At the same timethis magnetic field was swept from −500 [Oe] to +500 [Oe] as seen fromone of the east axis of the magnetization of the information storagelayer, the TMR element 1 was conducted in the direction perpendicular tothe film plane by adjusting a bias voltage applied to the terminal 23 ofthe word line WL and the terminal 24 of the bit line BL such that itmight reach 100 mV, and resistance values relative to external magneticfield values and TMR ratios were measured.

The TMR ratio was set to (R_(max)−R_(min))/R_(min) where R_(max)represents a resistance value obtained in the condition in which themagnetization of the magnetization fixed layer of the firstferromagnetic layer and the magnetization of the magnetization freelayer (information storage layer) of the second ferromagnetic layer areanti-parallel to each other and in which the resistance value is highand R_(min) represents a resistance value obtained in the condition inwhich the magnetization of the magnetization fixed layer and themagnetization of the magnetization free layer are parallel to each otherand in which the resistance value is low.

A measurement temperature was set to a room temperature of 25° C.

A coercive force Hc was calculated from a magneto-resistance R—externalmagnetic field H characteristic curve that had been calculated from thismeasurement method. A crystal structure was observed by a TEM(transmission electron microscope: Transmission Electron Microscopy). Inthat case, a crystal structure in which a grain boundary was notobserved from a bright field image of the TEM and in which a halo ringwas observed from an electron beam diffraction figure was determined asan amorphous structure.

A bias dependence was measured such that, while a bias voltage waschanged at the unit of 100 mV in a range of from 100 to 1000 mV, an R—Hloop was measured, a TMR ratio was calculated and a bias dependence wasplotted to the bias voltage.

Plotted results will be described below.

1. With Respect to Coercive Force and TMR Ratio

TMR-ratios and coercive forces of the information storage layers of theinventive examples 1 to 7 and the comparative examples 1 to 5 wereevaluated. Their evaluated results were shown and effects of the presentinvention will be described.

[1-1]. In the Case in which the Magnetization Free Layer of which theMagnetization is Inverted does not Contain Added Chemical Element Addedto FMTM (Transition Metal):

Specifically, the magnetization free layer of the comparative example 1had a conventional arrangement in whichCo₉₀Fe₁₀, Co₇₅Fe₂₅, Co₅₀Fe₅₀, Ni₈₀Fe₂₀

In that case, from observed results obtained by the TEM, it wasconfirmed that these materials are of crystal.

TABLE 1 Composition of Coercive force magnetization free layer Hc (Oe)TMR ratio (%) Co₉₀Fe₁₀ 40 37 Co₇₅Fe₂₅ 55 42 Co₅₀Fe₅₀ 60 40 Ni₈₀Fe₂₀ 2530

Although the inverted magnetic field Hc of the information storage layerin the TMR element 1 could be changed depending upon size, shape andthickness of the element, the size of the element 1 was determined suchthat the minor axis was fixed to 0.8 μm and the major axis was fixed to1.6 μm, magnetic material dependences of the TMR elements 1 in whichrespective magnetic materials were used to form the magnetization freelayers of the information storage layers were compared with each other.

Depending upon the structures of word lines and bit lines for generatinga current magnetic field, as the inverted magnetic field of themagnetization free layer of the TMR element increases, the write currentincreases. Therefore, reduction of the inverted magnetic field leads tothe decrease of the write current and the decrease of the powerconsumption.

Having compared the coercive force of the magnetic material of thecomparative example 1 enumerated on the table 1, Ni₈₀Fe₂₀ which might becalled a permalloy has the smallest coercive force Hc for influencingthe magnitude of the write current value, and it is to be understoodthat the write current value can be suppressed. This permalloy has a TMRratio of about 30%, which is small as compared with other materials.

For this reason, a read output voltage or output current becomesinsufficient. On the other hand, although the Co₇₅Fe₂₅ alloy has thelargest TMR ratio as compared with these materials, this alloy has alarge coercive force Hc so that write electric power increases.Specifically, it is to be understood that it is difficult to satisfy theread characteristic and the write characteristic at the same time.

When the magnetization free layer comprising the information storagelayer is composed of conventional crystal material, problems arise, inwhich the CoFe alloy, in particular, is not excellent in rectangleproperty of a resistance-magnetic field curve so that the invertedmagnetic field is changed each time it is measured, and therefore is notstabilized.

[1-2]. Effects Achieved when Single Substances of 3B-Group ChemicalElements to 5B-Group Chemical Elements are Added to the FMTM:

FIGS. 5A and 5B show measured results of coercive forces Hc and TMRratios for added amounts with respect to samples in which the FMTM wasfixed to Co:Fe=90:10 in atomic % and in which B, Si, Al, Ge that areadded 3B-group chemical elements to 5B-group chemical elements wereadded to this alloy while the added amount was being changed from 1 to40% in atomic % and samples having the arrangement of the comparativeexample 2 and in which. Mg and Zn which are other chemical elements than3B-group chemical elements to 5B-group chemical elements were added tothis alloy while the added amount was being changed in a range of from 1to 40% in atomic %.

In the arrangement in which B, Si, Al, Ge were added to the alloy, asthe added amount increases, the TMR ratio tends to increase temporarilyand to be lowered again. Then, it was confirmed that the invertedmagnetic field Hc was lowered by additions of Si, B, Al, Ge.

However, although the inverted magnetic field Hc is lowered by additionof Mg of 2A-group chemical element, the effects in which the TMR ratiosare increased in each of Si, B, Al, Ge could not be achieved.

When Zn of 2B-group chemical element was added to the alloy, neither theTMR ratio could be increased nor the inverted magnetic field Hc could bedecreased.

Specifically, according to the arrangement in which these 2A-groupchemical element and 2B-group chemical element are added, the increaseof the TMR ratio and the decrease of the inverted magnetic field, i.e.,the read characteristic and the write characteristic are not compatibleeach other and the above-mentioned alloy is not suitable for as thematerial of the magnetization free layer of the information storagelayer in a magnetic memory element.

While the effects achieved when B, Si, Al, Ge were added as the 3B-groupchemical element to 5B-group chemical element are shown in theabove-mentioned inventive examples of the present invention, it issupposed that similar effects could be achieved with respect to C, P,Ga, In, As, Se, Sn, Sb, Te located near B, Al, Ge in a periodic tableand whose features are similar, other metalloid chemical elements and3B-group and 4B-group metallic chemical elements.

As described above, while B, Si, Al, Ge and the 3B-group to 5B-groupmetalloid chemical elements and metallic chemical elements locatedaround these chemical elements in the periodic table and of whichfeatures are similar can achieve effects for improving TMR ratios anddecreasing coercive forces, of these chemical elements, chemicalelements such as B, Si, P, Al, Ge are particularly desirable.

From the results shown in FIGS. 5A and 5B, when the added amounts ofthese chemical elements are too small, the effects for improving TMRratios are small and effects for decreasing coercive forces are small.If the aforementioned effects are achieved, then at least more than 5atomic % of the 3B-group to 5B-group metalloid and metallic chemicalelements should be added. If the added amount is too large, thenalthough some added chemical element having an added amount of 40 atomic% can continue the coercive fore to decrease, the magnetization amountdecreases too much. As a result, there is a risk that the TMR ratio willdecrease. Even when the added amount exceeds 35%, there can be achievedthe effect that the magnitude of the coercive force Hc will decrease.However, in order to make the low coercive force become compatible witha high TMR ratio, it is to be desired that the added amount should notexceed 35%. Therefore, it is to be desired that the most suitable addedamount of the added chemical element that can improve the TMR ratio andmake it and the coercive force become compatible with each other shouldfall within a range of from 5 to 35 atomic % when one chemical elementis added to the FMTM.

Having observed TEM images of the cross sections of the magnetizationfree layer having the composition of the (Co₉₀Fe₁₀)₈₀B₂₀ of theinventive example in which the coercive force could be decreased and ofthe magnetization free layer having the composition of the(Co₉₀Fe₁₀)₉₇B₃ of the comparative example in which the effect fordecreasing the coercive force is small, it is to be understood that thefine structure of the (Co₉₀Fe₁₀)₈₀B₂₀ is an amorphous layer and the finestructure of the (Co₉₀Fe₁₀)₉₇B₃ is microcrystal. It is considered thatthe coercive force Hc can be decreased because the fine structure is themicrocrystal and amorphous layer.

As will be described in the magnetization decision behavior item thatwill be described later on, since the fine structure is the amorphouslayer, the rectangle property of the resistance-magnetic field curve canbe improved, the behavior of the magnetization inversion can bestabilized, and the dispersions of the magnetization inversion can bedecreased. From this standpoint, when the magnetization free layer isformed of the amorphous ferromagnetic material, the read characteristicscan be improved, and therefore the amorphous ferromagnetic material isthe suitable material as the magnetization free layer.

[1-3]. Effects Achieved by Addition of More than Two Kinds of 3B-Groupto 5B-Group Chemical Elements:

The effect for increasing the TMR ratio and the effect for decreasingthe coercive force according to the present invention can be achievedonly when only one kind of 3B-group to 5B-group metalloid chemicalelements is contained but also when more than two kinds of them arecontained.

The arrangement of the inventive example 2 contains more than two kindsof these chemical elements. FIGS. 6A and 6B show results obtained whenSi was selected as the first added chemical element, the added amountwas selected to be 15 atomic % and B, C, P, Al were added as the secondadded chemical elements. Even when the suitable material contains morethan two kinds of these chemical elements, it can be recognized that thecoercive force Hc can be decreased and the TMR ratio can be increased ashas been described in the above-described [1-2]. In particular, when Si,B and Si, Al are added at the same time, the coercive force Hc can bedecreased remarkably.

As described above, the TMR ratio can be increased and the coerciveforce can be decreased when the arrangement of the present inventioncontains one kind or two kinds of 3B-group to 5B-group metalloidchemical elements and metallic chemical elements.

Moreover, it is to be considered that similar effects can be achievedeven when the arrangement of the present invention contains more thanthree kinds of 3B-group to 5B-group metalloid chemical elements andmetallic chemical elements.

Therefore, 3B-group to 5B-group chemical elements are not limited inparticular, and one kind or more than two kinds should preferably beselected from B, C, Si, P, Al.

[1-4]. Composition Dependence of Ferromagnetic Transition Metal ChemicalElements Obtained When 20 Atomic % of B is Added to the Arrangement ofthe Present Invention:

Of the magnetization free layer material of the present invention inwhich chemical elements were added to make the magnetization free layerbecome amorphous, with respect to the composition ratios of Fe, Co, Niwhich are ferromagnetic chemical elements and TMR ratios and values ofcoercive force Hc, effects of the present invention will be describedwith reference to measured results of a sample in which 20 atomic % of Bin the inventive example 3 was added and a sample that does not use theadded chemical elements of the comparative example 1.

FIGS. 7A and 7B show measured results of the inventive example 3 and thecomparative example 1 altogether. In the sample in which B that is3B-group to 5B-group chemical elements of the present invention isadded, the composition ratio of any ferromagnetic transition metal ofCo₉₀Fe₁₀, Co₇₅Fe₂₅, Co₅₀Fe₅₀, Ni₈₀Fe₂₀ can increase the TMR ratio anddecrease the coercive force Hc as shown in the inventive example 1 ofthe aforementioned [1-2].

Therefore, these effects are not limited to the compositions of CoFe,NiFe, and such effects can be achieved with respect to a magnetic memoryelement including an alloy-based magnetization free layer in whichapproximately 5 to 35 atomic % of Al which is one of 3B-group to5B-group metalloid chemical elements are added to Fe, Co, Ni having anycomposition range.

Moreover, with respect to the added chemical elements, the arrangementof the present invention may contain not only N shown herein but also3B-group to 5B-group metalloid and metallic chemical elements and Al orthe added chemical elements of the present invention that will bedescribed later on.

[1-5]. Effects Achieved by Addition of One Kind of 4A-Group and 5A-GroupChemical Elements:

FIGS. 8A and 8B show composition dependences of coercive forces Hc andTMR ratios obtained when Ti, Zr, Nb, Ta of so-called bubble metals of4A-group and 5A-group metals are added to the FMTM in the sample havingthe arrangement of the inventive example 4.

The coercive force Hc can be decreased by the addition of these chemicalelements. With respect to the sample with the added amount of 15 atomic% in which the coercive force Hc can be decreased through the TEMobservation in which FMTM-Zr alloy was used in the magnetization freelayer, it is to be understood that this sample has the amorphous layer.On the other hand, with the added amount of 3 atomic %, the effect fordecreasing the coercive force Hc is small. It is considered that thereason for this is based upon the effect for making the sample becomeamorphous or making the crystal grain become fine. The coercive force Hccan be decreased in Ta, Zr, Nb as described above, and similar effectscan be achieved in so-called bubble metals of 4A-group and 5A-groupmetals. Although the added amount is not limited in particular so longas the above-mentioned effect can be achieved, from the experimentalresults shown in FIGS. 8A and 8B, the added amount should preferably beselected to be approximately 25 atomic % at the most in a range in whicha satisfactory TMR ratio can be obtained and the coercive force Hc canbe decreased. It is needless to say that similar effects can be achievednot only when these added chemical elements are solely added to the FMTMbut also at least one kind or more than two kinds of these addedchemical elements are contained in the samples.

[1-6]. Effects Achieved When 3B-Group to 5B-Group Chemical Elements and4A-Group and 5A-Group Chemical Elements are Added to the Samples:

FIGS. 9A and 9B show characteristic evaluation results obtained when 10atomic % of B is added to the TMTM and Ti, Zr, Nb, Ta are contained inthe sample of the inventive example 5. Having compared with the effectsachieved by the addition of the 3B-group to 5B-group chemical elementsin the inventive example 1, it is to be noted that, if these chemicalelements are further added, the coercive force can be further decreasedalthough the effects are small while the high TMR ratio obtained by the3B-group to 5B-group chemical elements is being maintained. It isneedless to say that these effects are not limited to Ti, Zr, Nb, Ta andit can be easily estimated that such effects can be achieved in Hf, vwhich are the 4A-group to 5A-group chemical elements that belong to thesame groups in the periodic table.

[1-7]. Multinary System:

If the effects shown by the measured results of the TMR ratio and thecoercive fore Hc are achieved, the arrangements of the inventiveexamples 1 to 5 should contain the above-mentioned 3B-group to 5B-groupchemical elements and the 4A-group to 5A-group chemical elements, thesearrangements may contain trace element of minute amount in addition tothe above-mentioned chemical elements.

FIGS. 10A and 10B show evaluated results obtained by the arrangements ofthe inventive example 6 and the comparative example 1. As illustrated,even the system which contains Cu in addition to the chemical elementsthat have been shown so far can decrease the coercive force Hc and canimprove the TMR ratio.

[1-8]. Substrate Temperature Obtained when Magnetization Free Layer isDeposited:

FIGS. 11A and 11B show the coercive force Hc and the TMR ratio relativeto the substrate temperature with respect to the sample having thearrangement of the comparative example 4 in which effects of substratetemperatures obtained when the magnetization free layer is depositedhave been examined. From the standpoint of conditions in which theamorphous layer is formed, the process for forming the magnetizationfree layer by heating the substrate exerts a bad influence upon thedecrease of the coercive force Hc and the improvement of the TMR ratiothat have been mentioned so far, and the result in which themagnetization free layer is deposited at room temperature is mostexcellent. Accordingly, from the view point of forming the amorphousstructure, it is not preferable that the substrate is heated when themagnetization free layer is deposited. Hence, the substrate temperatureshould be at least less than 100° C. and the substrate should preferablybe cooled.

[1-9]. Lamination Layer Structure:

FIGS. 12A and 12B show measured results of magnetization free layermaterials, the coercive forces Hc and the TMR ratios obtained when themagnetization free layers of the inventive example 6 and the comparativeexample 5 are formed so as to have lamination layer structures.

Coercive forces can be decreased and high TMR ratio can be achievedsimilarly by the magnetization free layers based on the lamination layerstructure of the amorphous layer formed by the addition of one kind ormore than two kinds of 3B-group to 5B-group chemical element metalloidand metallic chemical elements on the periodic table and the crystallayer. In this case, although the cause is not yet clear, the amorphouslayer should preferably be used for the side of the tunnel barrierlayer. When the crystal layer is laid adjacent to the side of the tunnelbarrier layer., as shown in FIG. 11 in the comparative example 4, thedecrease of the coercive force was not recognized.

2. Bias Dependence:

FIGS. 13A and 13B show bias voltage dependences of TMR ratios obtainedwhen the magnetization free layer is formed of the Co₉₀Fe₁₀ alloy of thecomparative example 1 and the magnetization free layer is formed of the(Co₉₀Fe₁₀)₈₀B₂₀.

FIG. 13A shows the bias voltage dependences in the form of measuredvalues, and FIG. 13B is a graph in which these measured values areplotted. Although the cause is not yet clear at present, when themagnetization free layer of the present invention is in use asillustrated, the bias dependence can be improved, the outputcharacteristic at real operation bias voltage can be improved so that itbecomes easy to discriminate the low-resistance state and thehigh-resistance state. As a result, the read characteristic of themagnetic memory element can be improved.

3. Magnetization Inversion Behavior:

Similarly in FIG. 14, a resistance-external magnetic field curveobtained when the magnetization free layer is formed of the(Co₉₀Fe₁₀)₈₀B₂₀ of the inventive example 1 and a resistance-externalmagnetic field curve obtained when the magnetization free layer isformed of the Co₉₀Fe₁₀ alloy of the comparative example 1 are shown bycurves 40 and 41, respectively. As described above, when the informationstorage layer of the present invention is used, the coercive force Hccan be decreased while the high TMR ratio can be maintained. Moreover,the rectangle property of the R—H loop can be improved, and theBarkhausen noise also can be decreased. As a result, not only the writecurrent can be decreased but also the shape of the asteroid curve can beimproved and hence the write characteristic can be improved, therebymaking it possible to decrease the write error.

FIGS. 15A and 15B show measured results obtained when asteroid curves of20 elements have been overlapped. FIG. 15A shows measured result whenthe magnetization free layer is made of (Co₉₀Fe₁₀)₈₀B₂₀ and FIG. 15Bshows measured results when the magnetization free layer is made ofCo₉₀Fe₁₀. As is clear from the results obtained when FIGS. 15A and 15Bhave been compared with each other, it is to be understood that, whenthe magnetization free layer is formed of Co₉₀Fe₁₀ which is theconventional crystal material, most of the asteroid curves is deviatedfrom the ideal asteroid shape. Hence, this magnetic memory is inferiorin read characteristic. However, when the magnetization free layer ismade of the amorphous ferromagnetic material of the present invention,the asteroid shape can become ideal and can be stabilized.

This effect can be achieved not only when the memory element uses themagnetization free layer having the material composition shown in FIG.15 but also when the amorphous ferromagnetic material in the range ofthe present invention is used in the main portion of the magnetizationfree layer. Therefore, according to the present invention, the writecharacteristic to the memory element can be improved considerably, andthe write error of the MRAM can be decreased.

Next, a specific circuit arrangement of an example of a magnetic memorydevice MRAM according to the present invention will be described withreference to FIG. 16 which shows a block diagram of a circuitarrangement. This MRAM comprises a cell array portion 160 formed by thearray of memory cells 11 and a marginal circuit portion 161.

The cell array portion 160 comprises a plurality of memory cells 11arranged in rows and columns. Each memory element includes a memoryelement 1 composed of MTJ and a transistor 13 that can select the cell.

The marginal circuit portion 161 includes decoders 162, 163 forselecting the cell from address information, drivers 164, 165 forcausing a write current to flow, a sense amplifier 166 for selecting aread current and the like.

Then, the marginal circuit portion 161 includes a bit line BL, a writeword line WWL and a read word line RWL, each of which is extended to thecell array portion 160. The bit line BL is connected to the decoder 162,and each memory cell 11 is accessed through the bit line BL.

Write operations, read operations in this magnetic memory device MRAMand respective arrangements thereof will be described.

[Write Operation]

In order to write information in the memory cell 11, it is necessary touse a magnetic field generated by a current. The lines BL and WWL areinterconnections necessary for causing a current to flow. The lines BLand WWL are located so as to cross each other in the upper and lowerdirection across the memory cell as mentioned hereinbefore. The drivers(inverters) 164 and 165 for applying a write current are connected toboth ends of the lines BL and WWL. The gates of the drivers areconnected to the decoders 162 and 163 for converting address datainputted from the outside and select the lines BL and WWL to which thewrite current should be applied.

In the line BL for generating the inverted magnetic field for invertingthe magnetization direction of the information storage layer 7 of thememory element, i.e., magnetoresistive effect element, the direction ofthe write current, i.e., the information write current of “0” or “1” maybe controlled based upon the data line input. On the other hand, in theline WWL for generating an assist magnetic field, although the directionof the write current may be constant, considering the electromigration,the direction in which the current flows can be inverted each timeinformation is written in the information storage layer.

[Read Operation]

The lines BL and RWL are used to read information from the memory cellin which information of “0” and “1” have been written as describedabove. A cell from which information is to be read out may be selectedby a transistor 13 provided in each memory cell. The gate of thetransistor is connected to the line RWL and the drain is connected toone end of the MTJ, respectively. Then, the other end of the MTJ isconnected to the line BL. The lines BL and RWL are connected to thedecoder and the lines BL and RWL thus selected for reading are alerted.A sense current may flow to the thus selected cell through the channelof the line BL, the MTJ and the transistor, and the magnitude of thesense current is detected by a sense amplifier 166. Specifically, “0”and “1” of recorded information may be discriminated from each other,i.e., recorded information may be read out from the memory cell.

In the magnetoresistive effect element in a magnetic sensor or the like,the magnetic memory element in the magnetic memory device according tothe present invention that have been described so far, when themagnetization free layer is composed of a single layer of an amorphousor microcrystal material or the main portion of the magnetization freelayer is composed of the amorphous or microcrystal material, morepreferably, the single layer of or the main portion of the magnetizationfree layer is composed of the magnetic material in which one kind ormore than two kinds of one or both of 3B-group, 4B-group and 5B-groupchemical elements or 4A-group and 5A-group chemical elements are addedto at least one kind or more than two kinds of ferromagnetic transitionmetal chemical elements Fe, Co, Ni on the periodic table.

According to this arrangement, as is clear from the above descriptions,in the magnetoresistive effect element, the rectangle property in theR—H characteristic may be made excellent and the noise may be decreased.Hence, this magnetoresistive effect element is suitable for use asmagnetic sensors for various applications such as a magnetic detectorand a magnetic head.

Moreover, in the magnetic memory element and the magnetic memory device,the read signal can be increased by increasing the TMR ratio, and thewrite current can be decreased. Further, when information is read outfrom the magnetic memory element or the magnetic memory device, the biasdependence characteristic of the TMR ratio can be improved and thenlow-resistance state and the high-resistance state can be discriminatedfrom each other with ease, thereby resulting in the read characteristicbeing improved. When information is written in the magnetic memoryelement or the magnetic memory device, the noise in theresistance-external magnetic field curve can be improved and the writeerror can be decreased. Specifically, both of the write characteristicand the read characteristic can be satisfied.

1. A magnetoresistive effect element comprising: a ferromagnetic tunneljunction having a tunnel barrier layer sandwiched between at least apair of ferromagnetic layers; and a magnetization free layer composed ofone of said ferromagnetic layers is comprised of a single layer of (1) amaterial having an amorphous or microcrystal structure or (2) a materiallayer of which the main portion is made of a material layer having anamorphous or microcrystal structure, wherein, said magnetization freelayer contains at least one kind or more than two kinds of 4A-groupchemical elements and 5A-group chemical elements on a periodic table andadded chemical elements of Cu, N, O, and S of which the content is lessthan 2 atomic %.
 2. The magnetoresistive effect element according toclaim 1, wherein said magnetization free layer contains at least onekind or more than two kinds of metalloid chemical elements and metallicchemical elements which are 3B-group chemical elements, 4B-groupchemical elements and 5B-group chemical elements on a periodic tablerelative to at least one kind or more than two kinds of components offerromagnetic chemical elements of Fe, Co, and Ni.
 3. Themagnetoresistive effect element according to claim 2, wherein saidmagnetization free layer uses any one kind or more than two kinds of B,C, Al, Si, P, Ga, Ge, As, In, Sn, Sb, Tl, Pb, and Bi as said metalloidchemical elements and said metallic chemical elements.
 4. Themagnetoresistive effect element according to claim 2, wherein saidmagnetization free layer uses any one kind or more than two kinds of B,Al, Si, Ge, and P as said metalloid chemical elements and said metallicchemical elements.
 5. The magnetoresistive effect element according toclaim 2, wherein said magnetization free layer contains said metalloidchemical elements and said metallic chemical elements of which thecontent lies in a range of from 5 to 35 atomic %.
 6. Themagnetoresistive effect element according to claim 3, wherein saidmagnetoresistive effect element contains said metalloid chemicalelements and said metallic chemical elements of which the content liesin a range of from 5 to 35%.
 7. The magnetoresistive effect elementaccording to claim 4, wherein said magnetization free layer containssaid metalloid chemical elements and metallic chemical elements of whichthe content lies in a range of from 5 to 35%.
 8. The magnetoresistiveeffect element according to claim 1, wherein said magnetization freelayer contains at least one kind or more than two kinds of 4A-groupchemical elements and 5A-group chemical elements on a periodic tablerelative to at least one kind or more than two kinds of component offerromagnetic chemical elements of Fe, Co, and Ni.
 9. Themagnetoresistive effect element according to claim 8, wherein saidmagnetization free layer uses at least one kind or more than two kindsof Ti, Zr, Nb, Hf, and Ta as said 4A-group chemical elements and said5A-group chemical elements.
 10. The magnetoresistive effect elementaccording to claim 8, wherein said magnetization free layer containssaid 4A-group chemical elements and said 5A-group chemical elements ofwhich the content lies in a range of from 5 to 25 atomic %.
 11. Themagnetoresistive effect element according to claim 9, wherein saidmagnetization free layer contains said 4A-group chemical elements andsaid 5A-group chemical elements of which the content lies in a range offrom 5 to 25 atomic %.
 12. The magnetoresistive effect element accordingto claim 1, wherein said magnetization free layer contains at least onekind or more than two kinds of metalloid chemical elements and metallicchemical elements which are 3B-group chemical elements, 4B-groupchemical element and 5B-group chemical elements on a periodic tablerelative to at least one kind or more than two kinds of components offerromagnetic chemical elements of Fe, Co, and Ni and also contains atleast one kind or more than two kinds of 4A-group chemical elements,6A-group chemical elements on a periodic table.
 13. The magnetoresistiveeffect element according to claim 1, wherein said magnetization freelayer has a main portion located on the side of said tunnel barrierlayer.
 14. A magnetic memory element comprising: a ferromagnetic tunneljunction having a tunnel barrier layer sandwiched between at least apair of ferromagnetic layers, and an information storage layercomprising a magnetization free layer composed of one of saidferromagnetic layers is made of a single layer of (1) a material havingan amorphous or (2) a microcrystal structure or a material layer ofwhich the main portion has an amorphous or microcrystal structure,wherein, said information storage layer contains at least one kind ormore than two kinds of 4A-group chemical elements and 5A-group, chemicalelements on a periodic table and added chemical elements of Cu, N, O,and S of which the content is less than 2 atomic %.
 15. The magneticmemory element according to claim 14, wherein said information storagelayer contains at least one kind or more than two kinds of metalloidchemical elements and metallic chemical elements which are 3B-groupchemical elements, 4B-group chemical elements and 5B-group chemicalelements on a periodic table relative to at least one kind or more thantwo kinds of components of ferromagnetic chemical elements of Fe, Co,and Ni.
 16. The magnetic memory element according to claim 15, whereinsaid information storage layer uses any one kind or more than two kindsof B, C, Al, Si, P, Ga, Ge, As, In, Sn, Sb, Tl, Pb, and Bi as saidmetalloid chemical elements and said metallic chemical elements.
 17. Themagnetic memory element according to claim 15, wherein said informationstorage layer uses any one kind or more than two kinds of B, Al, Si, Ge,and P as said metalloid chemical elements and said metallic chemicalelements.
 18. The magnetic memory element according to claim 15, whereinsaid information storage layer contains said metalloid chemical elementsand said metallic chemical elements of which the content lies in a rangeof from 5 to 35 atomic %.
 19. The magnetic memory element according toclaim 16, wherein said information storage layers contains saidmetalloid chemical elements and said metallic chemical elements of whichthe content lies in a range of from 5 to 35 atomic %.
 20. The magneticmemory element according to claim 17, wherein said information storagelayer contains said metalloid chemical elements and said metallicchemical elements of which the content lies in a range of from 5 to 35atomic %.
 21. The magnetic memory element according to claim 14, whereinsaid information storage layer contains at least one kind or more thantwo kinds of 4A-group chemical elements and 5A-group chemical elementson a periodic table relative to at least one kind or two kinds ofcomponents of ferromagnetic chemical elements of Fe, Co, and Ni.
 22. Themagnetic memory element according to claim 21, wherein said informationstorage layer uses at least one kind or more than two kinds of Ti, Zr,Nb, Ef, and Ta as said 4A-group chemical elements and said 5A-groupchemical elements.
 23. The magnetic memory element according to claim21, wherein said information storage layer contains said 4A-groupchemical elements and said 5A-group chemical said information storage ofwhich the content lies in a range of from 5 to 25 atomic %.
 24. Themagnetic memory element according to claim 22, wherein said informationstorage layer contains said 4A-group chemical elements and said 5A-groupchemical elements of which the content lies in a range of from 5 to 25atomic %.
 25. The magnetic memory element according to claim 14, whereinsaid information storage layer contains at least one kind or more thantwo kinds of metalloid chemical elements and metallic chemical elementswhich are 3B-group chemical elements, 4B-group chemical elements and5B-group chemical elements on a periodic table relative to at least onekind or more than two kinds of components of ferromagnetic chemicalelements of Fe, Co, and Ni and also contains at least one kind or morethan two kinds of 4A-group chemical elements and 5A-group chemicalelements on a periodic table.
 26. The magnetic memory element accordingto claim 14, wherein said information storage layer has a main portionlocated on the side of said tunnel barrier layer.
 27. A magnetic memorydevice comprising: word lines and bit lines crossing each other in athree-dimensional fashion; and a magnetic memory element composed of amagnetoresistive effect element located at a crossing point between saidword line and said bit line, said magnetic memory element being formedof a magnetoresistive effect element using a ferromagnetic tunneljunction having a tunnel barrier layer sandwiched between at least apair of ferromagnetic layers, and an information storage layer of amagnetization free layer composed of one of said ferromagnetic layersbeing comprised of a single layer of a material having an amorphous ormicrocrystal structure or a material layer of which the main portion hasan amorphous or microcrystal structure, wherein said information storagelayer contains at least one kind or more than two kinds of metalloidchemical elements and metallic chemical elements which are 3B-groupchemical elements. 4B-group chemical elements, 5B-group chemicalelements on a periodic table, at least one kind or more than two kindsof 4A-group chemical elements, 5A-group chemical elements on a periodictable and added chemical elements of Cu, N, O, and S of which thecontents are less than 2 atomics relative to at least one kind or morethan two kinds of ferromagnetic chemical elements of Fe, Co, and Ni. 28.The magnetic memory device according to claim 27, wherein saidinformation storage layer contains at least one kind or more than twokinds of metalloid chemical elements and metallic chemical element whichare 3B-group chemical elements, 4B-group chemical elements, 5B-groupchemical elements on a periodic table relative to at least one kind ormore than two kinds of ferromagnetic chemical elements of Fe, and Co.29. The magnetic memory device according to claim 28, wherein saidinformation storage layer uses any one kind or more than two kinds of B,C, Al, Si, P, Ga, Ge, As, In, Sn, Sb, Ti, Pb, and Bi as said metalloidchemical elements and said metallic chemical elements.
 30. The magneticmemory device according to claim 28, wherein said information storagelayer uses any one kind or more than two kinds of B, Al, Si, Ge, and Oas said metalloid chemical elements and said metallic chemical elements.31. The magnetic memory device according to claim 28, wherein saidmetalloid chemical elements content and said metallic chemical elementscontent of said information storage layer fall within a range of from 5to 35 atomic %.
 32. The magnetic memory device according to claim 29,wherein said metalloid chemical elements content and said metallicchemical elements content of said information storage layer fall withina range of from 5 to 35 atomic %.
 33. The magnetic memory deviceaccording to claim 30, wherein said metalloid chemical elements contentand said metallic chemical elements content of said information storagelayer fall within a range of from 5 to 35 atomic %.
 34. The magneticmemory device according to claim 27, wherein said information storagelayer contains at least one kind or more than two kinds of 4A-groupchemical elements, 5A-group chemical elements on a periodic tablerelative to at least one kind or more than two kinds of components offerromagnetic chemical elements of Fe, Co, and Ni.
 35. The magneticmemory device according to claim 34, wherein said information storagelayer uses at least one kind or more than two kinds of Ti, Zr, Nb, Hf,and Ta as said 4A-group chemical elements and said 5A-group chemicalelements.
 36. The magnetic memory device according to claim 34, whereinsaid 4A-group chemical elements content and said 5A-group chemicalelements content of said information storage layer fall within a rangeof from 5 to 25 atomic %.
 37. The magnetic memory device according toclaim 35, wherein said 4A-group chemical elements content and said5A-group chemical elements content of said information storage layerfall within a range of from 5 to 25 atomic %.
 38. The magnetic memorydevice according to claim 14, wherein said information storage layercontains at least one kind or more than two kinds of metalloid chemicalelements and metallic chemical elements which are 3B-group chemicalelements, 4B-group chemical elements, 5B-group chemical elements on aperiodic table and at least one kind or more than two kinds of 4A-groupchemical elements, 5A-group chemical elements on a periodic tablerelative to at least one kind or more than two kinds of components offerromagnetic chemical elements of Fe, Co, and Ni.
 39. The magneticmemory device according to claim 27, wherein said information storagelayer has a main portion located on the side of said tunnel barrierlayer.